Radio interference is an issue in wireless communications. For instance, capacity of a wireless channel depends on a ratio between signal power of a desired transmission to combined interference plus noise. Because of the broadcast nature of wireless communications, when two or more transmissions are conducted in vicinity, mutual interference is generated and collisions often occur. In a typical multiple-user environment, different users can sometimes interfere with each other.
In recent years, many research efforts have been devoted to interference management. For instance, various techniques center on interference avoidance. Interference avoidance attempts to scatter multiple transmissions along temporal, spatial and frequency dimensions to mitigate interference, e.g., where severe interference occurs. Other techniques employ interference cancellation, which attempts to recover transmission errors that are due to interference. Interference alignment and cancellation was developed to overcome the antennas-per-access point (AP) throughput by coordinating multiple APs.
In a typical multi-user environment, coordination among different users helps to avoid severe mutual interference and properly utilize shared media. However, such coordination can cost precious communication resources, and can lead to reduced network performance, even significantly degraded network performance. In traditional approaches, coordination is addressed in an either in-band or out-of-band manner. For in-band approaches, coordination traffic stays in a same communication channel as data traffic, bringing a large amount of communication overhead such as the Distributed Coordination Function Interframe Space (DIFS), Short Interframe Space (SIFS) and random back-offs in Carrier Sense Multiple Access (CSMA). Out-of-band approaches are typically designed for multiple radio systems. These approaches have conventionally dedicated one complete radio (and its associated channel resource) for coordination, and thus generate extra costs. In view of existing coordination techniques, effective coordination among multiple nodes without significantly wasting system resources has not yet been achieved.
The above-described deficiencies of conventional interference management techniques are merely intended to provide an overview of some of problems of current technology, and are not intended to be exhaustive. Other problems with the state of the art, and corresponding benefits of some of the various non-limiting embodiments described herein, may become further apparent upon review of the following detailed description.